31 research outputs found

    Certification of Cystatin C in the Human Serum Reference Material ERM-DA471/IFCC - Certified Reference Material ERM®-DA471/IFCC

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    The production of ERM-DA471/IFCC, certified for the mass concentration of cystatin C, is described. Serum was produced from blood collected in 2 collection centres according to a procedure ensuring that it was obtained from healthy donors, and that the lipid content of the serum was low. The serum was processed, spiked with recombinant cystatin C, and lyophilised. It was verified that the material is homogenous and stable. The material was characterised using a pure protein primary reference preparation (PRP) as calibrant. The PRP was prepared from recombinant cystatin C, and its concentration determined by dry mass determination. The characterisation of ERM-DA471/IFCC was performed by particle enhanced immuno-nephelometry, particle enhanced immuno-turbidimetry and enzyme amplified single radial immuno-diffusion. The certified cystatin C mass concentration in ERM-DA471/IFCC, if reconstituted according to the specified procedure, is 5.48 mg/L, the expanded uncertainty (k = 2) is 0.15 mg/L.JRC.DG.D.2-Reference material

    Bidirectional transfer study of polystyrene nanoparticles across the placental barrier in an ex vivo human placental perfusion model

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    BACKGROUND: Nanoparticle exposure in utero might not be a major concern yet, but it could become more important with the increasing application of nanomaterials in consumer and medical products. Several epidemiologic and in vitro studies have shown that nanoparticles can have potential toxic effects. However, nanoparticles also offer the opportunity to develop new therapeutic strategies to treat specifically either the pregnant mother or the fetus. Previous studies mainly addressed whether nanoparticles are able to cross the placental barrier. However, the transport mechanisms underlying nanoparticle translocation across the placenta are still unknown. OBJECTIVES: In this study we examined which transport mechanisms underlie the placental transfer of nanoparticles. METHODS: We used the ex vivo human placental perfusion model to analyze the bidirectional transfer of plain and carboxylate modified polystyrene particles in a size range between 50 and 300 nm. RESULTS: We observed that the transport of polystyrene particles in the fetal to maternal direction was significantly higher than for the maternal to fetal direction. Regardless of their ability to cross the placental barrier and the direction of perfusion, all polystyrene particles accumulated in the syncytiotrophoblast of the placental tissue. CONCLUSIONS: Our results indicate that the syncytiotrophoblast is the key player in regulating nanoparticle transport across the human placenta. The main mechanism underlying this translocation is not based on passive diffusion, but is likely to involve an active, energy-dependent transport pathway. These findings will be important for reproductive toxicology as well as for pharmaceutical engineering of new drug carriers. CITATION: Grafmueller S, Manser P, Diener L, Diener PA, Maeder-Althaus X, Maurizi L, Jochum W, Krug HF, Buerki-Thurnherr T, von Mandach U, Wick P. 2015. Bidirectional transfer study of polystyrene nanoparticles across the placental barrier in an ex vivo human placental perfusion model. Environ Health Perspect 123:1280-1286; http://dx.doi.org/10.1289/ehp.1409271

    The Ganymede Laser Altimeter (GALA) for the Jupiter Icy Moons Explorer (JUICE): Mission, science, and instrumentation of its receiver modules

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    The Jupiter Icy Moons Explorer (JUICE) is a science mission led by the European Space Agency, being developed for launch in 2023. The Ganymede Laser Altimeter (GALA) is an instrument onboard JUICE, whose main scientific goals are to understand ice tectonics based on topographic data, the subsurface structure by measuring tidal response, and small-scale roughness and albedo of the surface. In addition, from the perspective of astrobiology, it is imperative to study the subsurface ocean scientifically. The development of GALA has proceeded through an international collaboration between Germany (the lead), Japan, Switzerland, and Spain. Within this framework, the Japanese team (GALA-J) is responsible for developing three receiver modules: the Backend Optics (BEO), the Focal Plane Assembly (FPA), and the Analog Electronics Module (AEM). Like the German team, GALA-J also developed software to simulate the performance of the entire GALA system (performance model). In July 2020, the Proto-Flight Models of BEO, FPA, and AEM were delivered from Japan to Germany. This paper presents an overview of JUICE/GALA and its scientific objectives and describes the instrumentation, mainly focusing on Japan’s contribution

    The BepiColombo Laser Altimeter BELA and Tx Verification

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    BepiColombo is a mission to Mercury. The launch is scheduled for 2014. Onboard will be the BepiColombo Laser Altimeter (BELA) which is being developed and built in collaboration of the University Bern, Switzerland and the German Aerospace Center (DLR) in Berlin. The instrument's task is the global mapping of the planetary surface from an orbit in up to 1000 km height above the planet. Therefore the technique of measuring the travel time of light to the surface and back is used. As the speed of light is known very accurately the distance (range) can be calculated very simply. Questions about for example the geological evolution of Mercury or about the tidal movements shall be resolved. Especially the work on the laser transmitter part of the instrument is done by the DLR. This includes design, development and integration of the components as well as verification of the units. Precise alignment of the laser and the receiver telescope are mandatory for the functionality of the instrument. Extensive testing will be performed to assure this in the harsh Mercury environment. A testing setup therefore is designed and built up at DLR site in Berlin Adlershof

    Optical Performance Measurements of the BELA EQM and FM Transmitter Laser during AIV

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    The BepiColombo Laser Altimeter (BELA) onboard the Mercury Planetary Orbiter is Europe’s first built Laser Altimeter for a planetary mission. Its main objectives are global mapping of Mercury’s topography as well as measuring its tidal deformations to learn about the internal structure of this small terrestrial planet [1]. Crucial part of the instrument for this task is the transmitter laser. It must withstand all mission phases till operation in orbit and work within tight parameter margins. To ensure this a dedicated verification program has been performed at DLR Institute for Planetary Research Berlin which is described in the present paper

    First certified reference material for cystatin C in human serum ERM-DA471/IFCC.

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    The IFCC Working Group for the Standardisation of Cystatin C (WG-SCC), in collaboration with the Institute for Reference Materials and Measurements (IRMM), announces the availability of the new certified reference material ERM-DA471/IFCC. The material was characterised using a pure protein primary reference preparation (PRP) as calibrant. The PRP was prepared from recombinant cystatin C, and its concentration measured using dry mass determination. The characterisation of ERM-DA471/IFCC was performed by particle enhanced immuno-nephelometry, particle enhanced immuno-turbidimetry, and enzyme amplified single radial immuno-diffusion. The certified cystatin C mass concentration in ERM-DA471/IFCC, if reconstituted according to the specified procedure, is 5.48 mg/L, the expanded uncertainty (k=2) being 0.15 mg/L

    First Certified Reference Material for Cystatin C in Human Serum ERM-DA471/IFCC

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    The IFCC Working Group for standardisation of Cystatin C (WG-SCC) in collaboration with the Institute for Reference Materials and Measurements (IRMM) announces the availability of the new certified reference material ERM-DA471/IFCC. The material was characterised using a pure protein primary reference preparation (PRP) as calibrant. The PRP was prepared from recombinant cystatin C and its concentration determined by dry mass determination. The characterisation of ERM-DA471/IFCC was performed by particle enhanced immune-nephelometry, particle enhanced immuno-turbidimetry, and enzyme amplified single radial ummuno-diffusion. The certified cystatin C mass concentration in ERM-DA471/IFCC is 5.48 mg/L, the expanded uncertainty (k= 2) being 0.15 mg/LJRC.D.2-Reference material

    BELA transmitter performance and pointing stability verification campaign at DLR-PF

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    BELA is the first European planetary laser altimeter and shall be launched onboard of ESA's Mercury Planetary Orbiter (MPO) as part of the BepiColombo spacecraft in October 2018. The complete development of the in- strument was done in collaboration with team members in Switzerland, Germany and Spain. The transmitter is also the first space-qualified laser system for a planetary mission built in Europe. Highly important for scientific performance is the transmitter's performance which is specified with demanding values. Thermo-optical pointing stability, alignment, pulse energy, wavelength, pulse profile and length have a direct impact on the signal quality and strength of the instrument and in consequence on the quality of science data. Furthermore for in-orbit operation the detailed knowledge of the transmitter behavior is required for the interpretation of measurement data. Therefore the transmitter, an encapsulated diode pumped pulsed Nd:YAG laser, was extensively tested at facilities at DLR in Berlin-Adlershof under various environmental conditions in all possible representative configurations. This is necessary because thermo-elastic and optical behavior are difficult to predict accurately only theoretically. Furthermore there are temperature dependent effects, e.g. for laser energy, which directly affect science measurements and can only be calibrated on-ground. An optical test bench was designed and set up for this particular task. This work describes the test bench and the measurement procedures. The measure- ment results for the Engineering Qualification Model and Flight Model are presented and discussed as well as lessons learned. The outcome of the tests shows that the BELA FM transmitter performs well with margins and BELA is expected to achieve its scientific goals

    Preliminary Commutability Study on Candidate Reference Material for Cystatin C

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    Plasma (or serum) cystatin C has been proposed as a marker for the glomerular filtration rate, a measure of the capacity of the kidneys to filter plasma (GFR). Several studies, as well as one meta-analysis, have suggested that it is superior to serum creatinine for estimation of GFR. The IFCC working group for the standardisation of cystatin C has, in collaboration with the IRMM, prepared a candidate reference material (RM) for cystatin C. here the results from a preliminary study, performed in order to optimise the design of a planned large-scale commutability study, are presented.JRC.D.2-Reference material
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